This invention relates to the field of automotive engine rebuilding, and more specifically, to a gauge for measuring the degree of roundness of individual circular bearing seats, as well as the deviation of the center of curvature of a bearing seat with respect to a defined reference axis within an engine.
Equipment with camshafts, crankshafts, power shafts or other components with multiple journal bearings present a significant problem to the manufacturer or rebuilder of such equipment. The bearing seats frequently become misaligned from uneven wear, and occasionally are misaligned immediately after the initial boring. This problem gives rise to the need for a quick, accurate method of measuring the alignment of multiple circular bearing seats, as well as the degree of roundness of individual bearing seats, both during equipment rebuilding and immediately after initial manufacture.
In the automotive engine rebuilding industry, it is common to rebore the bearing seats of the crankshaft as a matter of course, because of the difficulty and expense in determining alignment. One method of measuring bearing seat alignment uses existing machinist's measuring tools and requires a complex setup and several hours of a skilled machinist's time. This method does not prove to be cost-effective for a small engine rebuilding operation.
An alternate method of gauging bearing seat alignment and roundness employs a precision-ground shaft which runs through the length of the engine block. The engine block has two main crankshaft bearing seats, into which the shaft is bolted by means of two main bearing caps. Machinist's layout blue is applied to the bearing seats. As the shaft rotates in the main seats, the presence of machinist's blue on the shaft indicates misalignment of bearing seats intermediate to the two main seats. Like the method noted above, this technique is very timeconsuming. Furthermore, it does not give a quantitative measurement of misalignment.